This is the fourth article in EnergyHub’s four-part “Avoiding Gridlock” series on how managed charging can mitigate the distribution impacts of EV charging. Don’t miss part one, The impact of electric vehicles on transmission vs. distribution systems, part two, The distribution impacts of EV charging, and part three, Why time-of-use (TOU) rates aren’t the long-term solution for managing local EV load.

Electric vehicle (EV) adoption is key to decarbonizing transportation, but presents significant challenges for the electric power industry. As more EVs hit the road, it is prohibitively expensive and time-consuming for the industry to upgrade millions of aging grid components in time to meet rising electricity demand from vehicle charging. 

Absent action, distribution substation and service transformers that cannot be replaced in time risk damage and failure. Simple system-wide EV demand response programs are a step in the right direction, but at scale they could have the same effect as EV time-of-use rates: power outages for customers and emergency replacement costs for utilities. 

Fortunately, utilities can supplement grid infrastructure upgrades with managed charging solutions. These solutions help utilities avoid EV charging gridlock, achieve reliability goals at a reduced total cost, and ensure customers get the charge they need.

How does EV managed charging work?

EV managed charging programs make it easy for utilities to manage distribution network voltages and avoid overloading distribution equipment, while drivers receive the desired charge within their specified timeframe. Most programs involve four core activities: forecasting, scheduling, real-time reconciliation, and reporting.

1. Forecasting. Managed charging integrates several data sets to forecast and harmonize charging times and intervals, leveraging the utility’s distributed energy resource management system (DERMS). These data include:

• Customer charging preferences, which drivers enter using a mobile app where they set a desired charging schedule and percent charge;
  
• Baseline load, forecasted from EVs and other DERs and the potential flexibility of that baseline load, based on historical data;

• Cost per hour, and eventually per minute, of serving the EV load, based on data from the wholesale market and other utility software systems; and

• Network constraints from other software systems, such as energy management systems (EMS) and advanced distribution management systems (ADMS).

2. Scheduling. The DERMS uses this data to produce a charging schedule. Drivers receive a charge by their scheduled departure time at the lowest possible cost to the utility, without violating grid constraints. 

3. Real-time reconciliation. The charging schedule is updated in real time as new data is ingested using advanced coordination algorithms. For example, EnergyHub’s managed charging solution systematically staggers when an EV will start and stop charging, given a utility’s priorities regarding cost management and infrastructure limits.

4. Reporting. The DERMS reports on the system’s performance so that utilities can understand the impact of managed charging from both operating cost and network management perspectives.

What’s the value of an EV managed charging program?

From the utility perspective, managed charging creates opportunities to meet drivers’ needs with low-cost electricity that doesn’t overload grid infrastructure. While the financial benefits of peak load reduction are modest for EVs compared to other distributed energy resources, managed charging programs also provide load shifting and distribution capacity benefits. 

Teams should incorporate these grid service benefits to comprehensively account for the value EV-based virtual power plants (VPPs) can deliver. For example, managed charging programs shift loads to reduce energy procurement costs and defer or avoid grid upgrades. Recent studies suggest these benefits could be worth several thousand dollars per EV compared to an unmanaged scenario. 

From the customer perspective, managed charging offers financial incentives and the ability to contribute to decarbonization efforts without interfering with vehicle use. A typical EV must charge for two to three hours daily but is plugged in for up to 12 hours. Enrolling in managed charging ensures that a customer’s car is fully charged when needed while supporting grid needs over those 12 hours. 

Drivers that use EnergyHub’s ChargingRewards app choose a time by which their vehicle must be charged each day and do not need to use the app again. The experience is more fluid than time-varying rates that require the customer to remember a schedule and stop and start charging sessions to comply. Instead, the vehicle’s charging schedule is automated and they receive an easy-to-understand incentive for participating in their utility’s managed charging program.

Start your managed charging program now

The power of managed charging can be achieved today using existing one-way smart charging (V1G) technology. EnergyHub has already enrolled several utilities across North America in managed charging programs, including Austin Energy, Eversource, and SMECO. 

Managed charging ensures that EVs spread their load throughout the typical evening-through-night charging period to minimize costs while meeting customer requirements. The result is a more strategic, fiscally responsible approach to grid infrastructure improvements that defrays costs for utilities and customers and boosts customer satisfaction.

Download our white paper for a full picture of the grid impacts of transportation electrification and how managed charging can turn EVs from an obstacle to an opportunity.

Download now.